[jira] [Updated] (KAFKA-14947) Duplicate records are getting created in the topic.

["krishnendu Das (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/KAFKA-14947?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

krishnendu Das updated KAFKA-14947:
-----------------------------------
    Attachment: Kafka_server_3.1.1_data_duplication_issue_log

> Duplicate records are getting created in the topic. 
> ----------------------------------------------------
>
>                 Key: KAFKA-14947
>                 URL: https://issues.apache.org/jira/browse/KAFKA-14947
>             Project: Kafka
>          Issue Type: Bug
>          Components: producer 
>    Affects Versions: 3.1.1
>            Reporter: krishnendu Das
>            Priority: Blocker
>         Attachments: Kafka_server_3.1.1_data_duplication_issue_log
>
>
> We are using Kafka connect API (version 2.3.0) and Kafka  (version 3.1.1) for data ingestion purposes. Previously we were using Kafka (version 2.6.2) and the same Kafka connect API (version 2.3.0). The data ingestion was happening properly. 
>  
> Recently we updated the Kafka version from 2.6.2 to 3.1.1.
> Post update we are facing duplicate data issues from the source connector into the Kafka topic. After debugging the 3.1.1 code, we saw one new function
> {*}updateCommittableOffsets{*}() got added and called inside the {*}WorkerSourceTask::execute{*}() as part of bug fix --"KAFKA-12226: Commit source task offsets without blocking on batch delivery (#11323)"
>  
> Now because of this function, we are observing this scenario
>  # Inside the execute() at the start of the flow, the call goes to updateCommittableOffsets() to check if anything was there to perform the committed offset or not. As the first poll is still not yet happened, this function didn't find anything for commit.
>  # Then Kafka connects API poll() method is called from the WorkerSourceTask::execute(). *---------> 1st poll*
>  # Kafka Connect API (using sleepy policy) reads one source file from the Cloud source directory.
>  # Read the whole content of the file and send the result set Kafka server to write to the Kafka topic.
>  # During the 2nd poll updateCommittableOffsets() found some offset to commit and its updates a reference variable committableOffsets, which will be used further by the WorkerSourceTask::commitOffsets() function to perform actual commit offset.
>  # Then Kafka connects the API poll() method is called from the *WorkerSourceTask::execute().* *---------> 2nd poll*
>  # Kafka Connect API (using sleepy policy) reads the same source file again from the start, as the offsetStrorageReader::offset() didn’t give the latest offset.
>  # Read the whole content of the file and send the result set Kafka server to write to the Kafka topic.---> These create duplicate data into the topic.
> ................................................
> ................................................
>  # WorkerSourceTask::commitOffsets() commits the offset.
> ................................................
> ................................................
>  # Then Kafka connects API poll() method is called from the {*}WorkerSourceTask::execute(){*}. ---------> 3rd poll
>  # This time offsetStrorageReader::offset() will be able to give the latest offset.
>  # Kafka Connect API (using sleepy policy) reads the same source file from the last read position.



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